Pyogenic streptococci--danger of re-emerging pathogens.

Area of Science:

• Microbiology
• Infectious Diseases
• Epidemiology

Background:

• Beta-hemolytic, pyogenic streptococci are classified into Lancefield groups A, B, C, and G based on surface antigens.
• Group A Streptococcus (Streptococcus pyogenes) is a major cause of global mortality.
• Increasing human infections by Groups B, C, and G streptococci (GBS, GCS, GGS) have been observed worldwide.

Purpose of the Study:

• To highlight the rising incidence of human infections caused by GBS, GCS, and GGS.
• To suggest a potential transition of GCS/GGS from animal to human pathogens.
• To underscore the underestimation of invasive pyogenic streptococcal infections in Poland.

Main Methods:

• Classification of streptococci based on Lancefield groups and major surface antigens.
• Review of global trends in human infections caused by pyogenic streptococci.
• Analysis of the shift in pathogenicity spectrum for GBS.

Main Results:

• Group A Streptococcus causes hundreds of thousands of deaths annually.
• GBS, GCS, and GGS are increasingly causing human infections globally.
• GCS and GGS, primarily considered animal pathogens, show a rising trend in severe human infections.

Conclusions:

• The increasing prevalence of GCS/GGS in human infections may indicate a zoonotic shift, similar to GBS.
• GCS/GGS warrant greater clinical attention due to their emerging role in human disease.
• Invasive infections by pyogenic streptococci in Poland are likely underreported and underestimated.